1. Field
The present invention relates to a three-dimensional (3D) ultrasound system of scanning an object inside a human body and a method of operating the 3D ultrasound system.
2. Description of the Related Art
An ultrasound system may transmit, from the surface of a human body, an ultrasound signal toward a predetermined portion inside the human body, for example, a fetus, an organ, and the like, to obtain an image associated with a section of soft tissue or the bloodstream by using information of the ultrasound signal having been reflected from tissue inside the body.
The ultrasound system has an advantage of being small, inexpensive, displayable in real time, and reliable since a subject is not exposed to an X-ray and the like and thus, the ultrasound system is widely used together with other image diagnostic devices, such as a computerized tomography (CT) scanner, a magnetic resonance image (MRI) device, a nuclear medicine device, and the like.
A fetus having Down's syndrome is generally identified based on a scheme of measuring a thickness of a nuchal translucency (NT) of the fetus. The scheme was designed by Nicolaides, in 1992. When the fetus has Down's syndrome, a thick NT is observed since body fluid is accumulated in a subcutaneous tissue of a neck.
Specifically, when the fetus has a chromosomal anomaly or a deformity of the heart, a thick NT is often observed. Therefore, a physician may measure a thickness of the NT of the fetus through the ultrasound system, and may observe the fetus using a Chorionic Villus sampling scheme or an amniocentesis scheme when the thickness is over 2.5 mm.
As another scheme of identifying Down's syndrome in a fetus, an angle between the palate and the dorsum nasi, namely, the frontmaxillary facial (FMF) angle, may be measured. The FMF angle of a normal fetus is 78.1 degrees, and a fetus having an FMF angle of 88.7 degrees has a high possibility of having Down's syndrome. There are various schemes for identifying Down's syndrome, such as measuring the biparietal diameter (BPD), Head Circumference (HC), Abdominal Circumference (AC), Femur Length (FL), and the like. A gestational age and a weight of the fetus may be estimated based on the schemes.
A process of obtaining an accurate sagittal view from ultrasound data needs to be performed in advance, to identify Down's syndrome in the fetus by measuring the thickness of the NT and the FMF angle between the palate and the dorsum nasi.
Conventionally, however, the sagittal view is determined based on experience of the physician and thus, the measured thickness of the NT of the fetus or the FMF angle between the palate and the dorsum nasi may be different from an actual thickness and an actual angle. Accordingly, there has been a difficulty in making an accurate diagnosis.